Elongated sections of pipe are commonly used to form long pipelines for delivering fluids from one location to another. Such fluids include, for example: natural gas, water, oil, and other flowable materials. Pipelines for carrying such materials often extend for miles in shallow, covered trenches. The trenches are typically, but not always formed along roadways, fence lines, railroads or power line right of ways.
A typical pipeline construction begins with digging the trench. Sections of pipe are then delivered to areas along the trench. The pipe sections are often delivered in banded bundles at intervals spaced by distances calculated to include the total length of the sections in a single bundle. Alternatively, selected numbers of pipes are deposited in groups along the trench. Single sections are not often spread along the ground because of the difficulty and time consumed in manually moving individual sections from the carrier.
The individual pipe sections are taken from the bundles or groups, and are moved along the trench, usually by a truck or tractor, to points where they are to be connected to the end of the pipeline being formed in the trench. This often means a crew must: (1) move to a bundle, (2) undo the bundle, (3) select one or more sections, (4) move the sections to the proper spot along the trench, (5) set the sections in place (where another person or crew joins the section ends together). The process then starts over again for the next sections to be placed in the trench.
Obviously the above process for setting the individual pipe sections in a semblance of end-to-end relation for joining is a time consuming and tedious process. A need clearly exists for an improved apparatus by which individual pipe sections may be delivered successively for joining in a pipeline. It is also desirable to join the individual sections as they are delivered from the carrier.
Various forms of joining tools have been developed for joining the individual pipe sections in end-to-end relation. Such tools typically are independent of the pipeline delivering vehicles. Separate transport is required for joining machinery that must be moved forward in increments as the pipe sections are joined. The additional support equipment adds expense and personnel to the construction endeavor.
The need for pipe section delivering equipment has been recognized, but has not been successfully filled by prior known apparatus.
For example, U.S. Pat. No. 2,780,376 to Sanders discloses a machine for continuously joining pipe sections in which a trailer for supporting a stack of irrigation pipe sections is attached to a towing vehicle. An elaborate escapement mechanism is provided centrally under the pipe section stack. A zig-zag passageway for the pipe sections is provided, leading downwardly to the escapement mechanism, to assure a single file stack of pipe sections are delivered to the escapement.
The Sanders mechanism and the required feed arrangement takes up a significant amount of space on the trailer that could otherwise be used for the stack of pipe sections. Further, the central, under-frame location for dispensing the sections is not desirable when pipe sections are to be connected end-to-end in a trench to one side of the trailer as needed in pipeline construction. Still further, no provision is made to mount any form of joining mechanism to the dispensing trailer.
An apparatus for handling irrigation pipe similar to the Sanders machine is shown in the 1975 U.S. Pat. No. 3,858,731 to Briggs. Side discharge for irrigation pipe sections from a single tier stack on a trailer is shown in the 1972 U.S. Pat. No. 3,685,670 to Meyers.
U.S. Pat. No. 2,935,214 to Fly discloses an apparatus for attachment to a standard pipe or other "elongate materials" hauling trailer. The apparatus includes a linkage and operators that can be used to pick the top pipe section from a stack on the trailer and deliver it to the ground surface alongside of the trailer. Conversely, the apparatus may also be used to pick a pipe section up from the ground and deliver it to the top of the stack on the trailer. No disclosure is made regarding removal of the pipe sections longitudinally of the stack, nor is there disclosure of any form of device or apparatus on the trailer for aiding joining of the sections together.
Another side dispensing pipe section hauling trailer is disclosed in U.S. Pat. No. 3,587,885 to Hanway. Side mounted roller guides are mounted to the trailer frame to receive and longitudinally guide pipe sections from a necessarily small stack of sections on the trailer bed. No escapement mechanism is disclosed between the stack and trailer bed, so the stack will feed freely to the guide rollers.
U.S. Pat. No. 4,541,767 to Daberkow teaches a pipe loader/unloader conveyor that may be releasably attached to the side of a trailer bed for the purpose of aiding a worker in loading successive pipe sections by moving engaged pipe section ends up and laterally onto the trailer bed. The device may also be used for unloading the trailer. No longitudinal movement of the pipe sections, or joining of successive sections is provided for.
U.S. Pat. No. 3,956,901 to Brown discloses a composite machine for placing sewer tiles in a pre-formed trench. Among many other provisions, the Brown machine includes a tile storage and delivery apparatus, for delivering successive tiles into the formed trench where they are then joined to form a sewer line.
Brown's tile dispensing mechanism includes a central longitudinal roller conveyor mechanism that is fed successive tile lengths from the top of a stack by operation of an escapement mechanism. The escapement mechanism is comprised of vertically movable "knife" blades that are positioned laterally adjacent the top tiles of stacks which are laterally disposed to opposite sides of the roller conveyor. The tiles in the layers rest on racks that are inclined inwardly toward the roller conveyor.
Brown's escapement blades are successively raised and lowered to allow individual tiles to roll onto the inclined roller conveyor, which then guides the received tiles downwardly to a lowering hoist. No pipe sections are removed to the side of the frame, and no provision is made for carrying a joining mechanism on the frame for successively joining the sections together.
Another guide roller conveyor used to guide pipe sections downwardly into a trench is disclosed in U.S. Pat. No. 3,565,269 to Martin. The roller conveyor is mountable to the side of a trailer and is provided with a catwalk for enabling workers to stand while lifting successive pipe sections from a stack on the trailer to the conveyor. No escapement mechanism is thus disclosed, nor is there a suggestion of apparatus to mount a section joining device, since the disclosure exemplifies use with drain tiles that require no end joining procedures.
Gable et al. in U.S. Pat. No. 3,757,927 discloses a bar stock storage dispensing and feeding apparatus that is situated in a stationary position relative to metal working equipment such as a lathe, to feed successive lengths of bar stock to the lathe. A circular, slotted magazine mechanism is used to receive and store successive groups of bars fed one at a time from a bar support rack.
Gable et al. do not disclose the device in connection with mounting to a pipe section hauling trailer, nor are there provisions indicating utility of the magazine as an escapement mechanism adjacent a stack of bar sections. To the contrary, the Gable et al. magazine itself constitutes a storage device.
Even with the above numerous attempts at a solution to the problem of adequately dispensing pipe sections from a trailer, a need remains for a trailer with structural features that will facilitate dispensation and, if desired, joining of successive pipe sections as they are delivered.